February 15, 2014

Arctic Animals Are Sentinels For Climate Change

Being particularly sensitive to carbon monoxide and methane, canaries were often used by miners as sentinels to determine if the toxic mine-related gases were building up to dangerous levels.

Speaking this week at the annual meeting of the American Association for the Advancement of Science in Chicago, oceanographer Sue Moore said walruses, polar bears and seals can be looked at in much the same way, in that well-being of these Arctic animals are essentially early-warning systems for determining the state of Arctic ecosystems being affected by climate change.

"Marine mammals can act as ecosystem sentinels because they respond to climate change through shifts in distribution, timing of their movements and feeding locations," said Moore, a biological oceanographer at the National Oceanic and Atmospheric Administration (NOAA). "These long-lived mammals also reflect changes to the ecosystem in their shifts in diet, body condition and physical health."

Moore also emphasized the importance of incorporating marine mammal health research into the overall study of changes occurring in the Arctic.

"Marine mammals connect people to ecosystem research by making it relevant to those who live in the Arctic and depend on these mammals for diet and cultural heritage and people around the world who look to these animals as symbols of our planet's health," she said.

Released in November, the annual NOAA Arctic Report Card for 2013 said the extent and aspects of the Arctic ecosystem were closer to their long-term averages over the past year, but the impacts of a prolonged warming trend that began over three decades ago remain evident.

The report card also said relatively cool atmosphere temperatures in summer 2013 across the Arctic Sea, Greenland and northern Canada facilitated an increase in the summer sea-ice magnitude and a decline in the level and duration of melting for Greenland surface ice. Conversely, last summer was one of the warmest on record in Alaska, where new record highs were set at some permafrost observatories, and the center of the state experienced a record 36 days with temperatures of 80 degrees F or warmer.

The report also concluded that the longer-term effects of the warming climate on the natural habitat are influencing the Arctic ecosystems, citing evidence throughout the entire food web. The capability to more effectively gauge, monitor, document and attribute these shifts depends on a prolonged increase in the quantity of extensive surveys and regular long-term observing programs, the NOAA reviewers said.

“The response of the physical environment system to the persistent warming temperatures is having an impact on the marine ecosystem,” a NOAA statement on the report card said. “New fish species have also been reported in several areas, especially the Canadian Beaufort Sea, which likely represents both altered distributions resulting from climate change and previously occurring but undetected species.”

“As with the marine environment, the assessment of climate change impacts on arctic wildlife is complicated because these land-based communities respond to a host of other factors, including disease, hunting rates and changes to management regimes,” the statement continued. Consequently, studies of large land mammals convey a mixed message.”